1. Field of the Invention
This invention relates generally to the field of wireless communication devices and to methods of improving the efficiency of transmission from such devices. More particularly, this invention is directed to devices which employ infare trnsmssion. An example of this type of device is a wireless keyboard for use with a personal computer.
2. Descripton of the Related Art
Various wireless keyboards and other remote control devices have been proposed by others. However, the degree of acceptance by the public of these devices has been limited in that the reliability of the "connection" between the remote, such as the keyboard, and the host (e.g., a computer) can at times be intermittent due to obstacles or incomplete communication from the remote to the host.
Wireless systems that employ an RF transmitter, such as is shown in Kendall et al.'s U.S. Pat. No. 4,775,928, suffer from various problems such as limited frequency bandwidth availability, interference, dead zones and the like.
Optical systems using a single LED as an infra-red driver, such as is shown in Lin et al.'s U.S. Pat. No. 5,189,543, suffer from other problems such as a possible intermittent light path to the receiver.